Science for a Dangerous Planet

Science for a Dangerous Planet

 

Linda Gundersen: Good evening. Thanks for coming to the USGS Public Lecture Series tonight and braving the heat. I hear it was 106 up in Baltimore today, so I hope you are ready for a very cool talk on this hot night.

I am Linda Gundersen. I am the acting Associate Director for Geology. And we hope that this Science in Action Lecture Series gives you all a better understanding of the science-based issues that are meaningful to us in our everyday lives.

Our speaker tonight is Dr. David Applegate. He is the Senior Science Advisor for Earthquake and Geological Hazards here at USGS. And he also leads the Earthquake Hazards Program, the Geomagnetism Program, and the Global Seismographic Network.

David was born and raised in Chambersburg, Pennsylvania. And he came to be a geologist through both the encouragement of his older brother to take a geology course while he was in college and a gift from his brother, John McPhee's marvelous book, "Basin and Range". This imparted an adventure-filled and romantic view of a geologist's life to David.

 01:09

And in completing his Bachelor's Degree in Geology at Yale and his Ph.D. in Geology at Massachusetts Institute of Technology, David got to enjoy many years of fieldwork in such places as the Hoback Range of Wyoming, the Pioneer Mountains of Idaho, the Olympic Mountains of Washington, the Bitterroot mountains of Montana and the Funeral Mountains of California that only reinforced that romantic view of the geologist and hooked David for life.

David has a strong sense of how important the earth sciences are to our everyday life. And prior to joining USGS, he worked at the American Geological Institute as Director of Government Affairs and Editor of Geotimes Magazine. He also has extensive experience on the Hill. He served as the American Geophysical Union's Congressional Science Fellow and also as a professional staff member on the Senate Committee on Energy and Natural Resources.

 02:08

Tonight, he is going to share lessons learned from a recent string of earthquakes in Haiti, Chile and elsewhere. Please join me in welcoming Dr. David Applegate.

[Applause]

David Applegate: Well, thank you very much for that introduction. Can you all hear me well enough? There in the back row? All right. Marvelous. Marvelous. Well, then, thank you all for coming out this evening. I very much appreciate that.

Now, I should say upfront that you should forgive me for such an alarming title, Science for a Dangerous Planet. But it is a dangerous planet. Earth goes about its business through extreme events. The very processes that have shaped and built the landscape that we know today is a result of extremes.

 03:05

These hazards have been with us since, well, before we were with us. But it is the disaster that is the construct of that interaction of these long-standing processes with humans and with the building environment that we have constructed.

And as with all things that are dangerous, we must handle with care. And part of that careful handling is that when extremes do occur that we learn from them so that when we face them again, we are going to be better-prepared and better able to deal with it, become a more resilient society.

Now, the oil spill in the Gulf of Mexico has pretty much dominated the news. Indeed, it has pretty much dominated everything here at this agency as you might well expect. And it almost gets hard to remember what the first few months of this year were like.

 04:03

But by the time April rolled around, we have had so many large damaging earthquakes. We actually had to put out a press release to reassure people that we really were not having that many large damaging earthquakes, it was not the end times, that we were still within the range of normal. Of course, what was extraordinary wasn't so much the number of magnitude 7 or greater quakes; it was the impacts and the location.

What this chart shows here, this is all the magnitude 7, 8 and 9 earthquakes over the past century, just all them run together. And then down in the bottom is looking at four-month windows of the first four months, the second four months, the third four months of each year out over that same time period. And we've had six, almost seven magnitude 7 earthquakes, which puts us right in that red line.

You can see that there are many years in which we actually had more events than this year. But, again, impacts are what made it so striking.

 05:08

Now we put that announcement out on April 15th. It was about a day or two later that a small, completely unpronounceable volcano in Iceland promptly proceeded to erupt and shut down all the airspace over Europe for several weeks.

And at that point, I think we began to wonder about putting out releases, telling people that there was nothing unusual going on.

[Laughter]

David Applegate: And we considered maybe we should be taking a different tactic and just admitting that maybe the Mayans were right. But we thought better of it.

Well, hazards are a key part of the USGS mission. When we think about earthquakes, volcanoes and other natural hazards, you will look to the USGS to help in understanding the world and what it's about. And hazard science is a key element of our mission. It's a key element of our strategy for the future, which is shown here.

 06:09

And the components of that are, first, a robust monitoring capability, second, the ability to assess both hazards and their impacts, and finally, the science to understand the processes that are driving these impacts. The processes then can lead us to a better understanding, a better ability to forecast the events before they happen.

And all of this is done very much through partnerships both with federal agencies, with universities, with the private sector as we try to tackle these difficult societal issues.

Now, the USGS has some very specific statutory roles and responsibilities. For the geologic hazards, we've got the delegated federal role for issuing alerts and warnings for earthquakes, volcanoes and landslides. But for a whole host of other hazards, we also play a very significant role in support of others.

 07:06

In the case of, for example, tsunamis, the seismic networks that we maintain that feed information to our National Earthquake Information Center, that data also flows to NOAA's tsunami warning centers so that they can take that information and then combine it with their buoys and other capabilities and be able to issue tsunami alerts.

USGS stream gauges and storm surge monitors are actually crucial for the ability of NOAA to be able to issue flood warnings, to do their hurricane surge assessments and so forth. And we actually maintain a series of geomagnetic observatories in the US and its territories. They are the key ground base component of the monitoring and tracking of space weather.

And if these earthquakes and volcanoes sound exciting, we've got a solar cycle that's ramping up that we should have a solar maximum coming in a year or so. And with the increased sun spots, increased solar flares and, who knows, maybe they can actually top the rest of us in that.

 08:12

And then finally our geospatial capabilities support all of these different hazards. In particular I singled out wildfires because of the role the USGS plays in providing the remote sensing and other geospatial tools for the other land management agencies and the Department of the Interior and the Department of Agriculture, the US Forest Service, to help them in their efforts to deal with and combat with wildfire.

So it's quite a range of roles and responsibilities.

Now focusing specifically on earthquakes, we're part of a partnership, and we've been part of this since 1977 when Congress established the National Earthquake Hazard Reduction Program. The whole idea of this is to make a handoff from fundamental research that's done in an agency like the National Science Foundation passed off through an agency like the National Institute of Standards and Technology and the Federal Emergency Management Agency to improve engineering practices and ultimately building codes.

 09:08

The USGS role in this handoff is, first and foremost, similar to the strategy that I talked about. It's monitoring responsibilities, hazard assessment responsibilities, and the targeted research that we need to do to be able to carry each of those out. And then the final piece, which is crucial, is then communicating that to the public and helping them to understand the hazard.

Now, people tend to think of earthquakes as being maybe a California thing, maybe a West Coast thing. And certainly, the majority of earthquake hazard is indeed out in the west, because the majority of earthquakes, just like volcanoes, tend to occur on plate boundaries.

And we've got the western US, we have the boundary between North America and the Pacific plate. In the case of the Pacific Northwest and Alaska, we have plates colliding against each other, the oceanic crust diving down beneath the North American continent. In the case of California, of course we have the plates sliding against one another in the famous San Andreas fault that makes up that plate boundary.

 10:16

But earthquakes are not limited to plate boundaries. And in fact, these earthquakes that occur in the inner parts of the continents, they can be less frequent, but they can be more damaging. And I'll talk a bit about some of the reasons for that.

This just shows a number of earthquakes that occurred in about the last two, two and a half years against what is our real flagship product when we think about how we convey earthquake hazard.

And this is our National Seismic Hazards Assessment, and what it's showing is, over a 50-year period, these are the accelerations from strong ground shaking that we can expect to experience in different parts of the country. And essentially this hazard map is a compilation of everything that we know about earthquake hazard here in the US.

 11:04

It includes seismicity, so where earthquakes have been recorded by seismic networks. It includes all of the active faults that geologists have gone out and measured. It includes geodesy using super precise GPS networks that actually watch the earth's crust move in real time and see how that develops over time.

And then finally, the last piece of that is called attenuation relations, and what that means is simply how strong the shaking is at the location of the earthquake and how that shaking intensity decreases with distance. It's not just right at the fault that matters; it's also how that shaking varies as it moves away, and that's one of the areas where there's a real difference between, say, mid-continent earthquakes and those out on the boundary.

So these maps are everything that we know about the hazard. And this is the key handoff. These maps go into seismic provisions that are then fed into building codes.

 12:07

We don't have a national building code in the US. What we have is a model building code that then is adopted by states and localities. And this is probably the most important aspect of mitigation of the earthquake hazard is the ability to build structures that can withstand the kind of shaking that we expect to happen.

The Holy Grail has always been earthquake prediction, the ability to make a short-term prediction that, 'Tomorrow we're going to have a magnitude 6 earthquake in this place.' In fact, I get emails on a pretty daily basis from folks who are trying, and earthquakes have defied that. In fact, it may be that earthquakes can't be predicted in that whack manner.

A big earthquake is just a small earthquake that keeps on going, keeps on rupturing. The longer the fault rupture, the bigger the earthquake. So there's some that think we may never be able to predict earthquakes. But by being able to predict where earthquakes can occur, we can have a built environment that's resilient to that.

 13:07

And you shouldn't take our word about all those things that we throw into understanding what the hazard is. Take the word of the one-and-a-quarter million people who've come to our website over the past 10 years to tell us what they experienced, to tell us what they felt in earthquakes.

They come in, they answer a series of questions about the shaking intensity, and that's what this map is showing with sort of blue colors being lighter and oranges and reds being more intense shaking. They've come in and told us what they've experienced. And you can see it really starting to fill in. Just in a 10-year period, it's starting to fill in that National Hazard Map that shows the expected shaking over a 50-year period.

And this is where I want to point out the difference that I was describing. So I'm going to compare two earthquakes, one that occurred two years ago right on the Illinois-Indiana border, which was a magnitude 5.2 earthquake, and the other which occurred this April, and this was the magnitude 7.2 quake that hit Baja, California, just south of the California border.

 14:11

Well, we had 77,000 people come on our site and tell us what they experienced in the Baja earthquake. And you can see that those people who were reporting from closest into the earthquake itself experienced quite strong shaking. But as you get further out and further out, you see more reports that are fairly light shaking. And here's the scale down here.

And that's one point I ought to make. When we talk about the magnitude of an earthquake, that's an expression of the total amount of energy that's released in that event. Each unit is 10 times greater than the next unit. So a magnitude 7.2 earthquake is a hundred times bigger than a magnitude 5.2 earthquake. But the actual amount of energy that's released goes up by a factor of 33 for each unit. So we're talking about an earthquake here that's a thousand times more energy released on the left than the one on the right.

 15:02

And yet you look and you can see that the felt reports at a distance are actually in some cases stronger from that much smaller earthquake. And that's because out in the west, the crust is a plate boundary, the crust is all crumpled up and broken up. In the central and eastern US, the crust is old, it's cold, really it rings like a bell, transmits energy very well.

And you think of things like the Mississippi River Valley, you have all these thick sediments that have accumulated and they shake like the proverbial bowl full of jelly. So for both of those reasons, a smaller earthquake in the central and eastern US is going to have impacts over a much broader area than a larger one in the west.

Just a couple of weeks ago, on June 23rd, there was a magnitude 5 earthquake just north of Ottawa. It was located in Quebec. We got over 56,000 felt reports from that. They came from 19 different states and from four to five Canadian provinces, so looks like from over 3,000 zip codes in the US and 357 towns and cities in Canada. So, again, a small earthquake felt over a very broad area.

 16:22

And the reason this is a big deal to us is that these earthquakes, again, when we have a large earthquake occurring in the central and eastern US, there is the potential for significant damage over a very broad area.

And we're just coming up on the bicentennial next year of the Great New Madrid Earthquakes. This was a sequence of earthquakes, they were magnitude 7 or greater earthquakes that struck the central US, struck in the Mississippi River Valley, the first one on December 16th, big aftershock that night, and then two more, one in January and one in February of 1812. 

 17:02

Now back then, there was about 400 people living in the region. Of course, now we have cities like Memphis, St. Louis, and tremendous concentrations of population, of key infrastructure that connects the southern and northern parts of the country all running through there. So we have a teachable moment coming up with this bicentennial that we very much need to seize to help awareness that the earthquakes are an ongoing hazard.

Now, in addition to these felt reports where people come on our website and tell us what they feel, we've actually started to use what people tweet. So after an earthquake, there are lots of people, especially in places like California, who their first instinct is to tweet about it. And literally you get, this is in just the minutes after a fairly small, I think this is a magnitude 4.5 or so earthquake in Southern California.

Now the fact that somebody just said that they were woken up by the earthquake, that's not really that interesting to us, but what is interesting is that these are geolocated, so we can actually watch as the people report feeling the earthquake. We can see the earthquake propagating out. And it's a nice check against the instrumental records that we're generating from our networks. So this is the Brave New World.

 18:25

And, indeed, this is all part of the next effort that we're engaged in. So the one part is the long-term hazard, really trying to improve the built environment, and the second part is in, after an earthquake occurs, trying to provide the fastest possible information and this robust information to the emergency responders to enable them to focus on their response activities and save lives.

And we do this domestically and we do it globally. So our National Earthquake Information Center out in Golden, Colorado is 24/7 operation. They use a global seismographic network which is 150 stations around the world on islands and very isolated places. We've got folks down in Albuquerque who maintain these stations. It's a partnership between the USGS, the National Science Foundation, and a university consortium known as IRIS.

 19:19

In the US, we maintain a national backbone of sensors. We also have regional networks in areas of high hazard. And finally, we actually instrument buildings all over the country to be able for engineers to learn from what the building experience is, like the black box on an airplane where the first thing they do after an accident, they want to learn everything about what that airplane experienced. Well, the same thing is true for engineers. They want to learn everything about what a building experienced so we know how to build it better.

The first thing we send out as an earthquake notification, this is a text message or an email. There are over 175,000 users of this. Anybody can sign up. The URL is right there. It's pretty easy to set yourself up. You can customize it. You can choose the area that you want; you can have the whole US, you can just be interested in earthquakes in Utah. You can set your thresholds high or low. You can have different settings for nighttime and daytime. Very customizable. And it's the first piece of information that we generate.

 20:28

But in a sense, what we used to do is that's where we'd stop. We'd say, 'Yep, an earthquake happened. Here's the location of it. Here's how deep it was. Here's how big it was.' But what we really want to get to is where was the shaking, where do you need to focus your efforts.

And so the next product that we generate is called a ShakeMap. And the Governator has very kindly agreed to demonstrate our ShakeMap here. This was after the 5.4 Chino Hills earthquake that was very broadly felt in Los Angeles a couple of years ago. And you can also see it up on the big boards there at the LA Country Emergency Operation Center. So this is not just giving you a single location; it's actually telling you where the shaking is most intense, and therefore where to focus efforts.

 21:16

And we have a separate system called ShakeCast that actually critical users, they use it behind their own firewalls. For example, the Department of Transportation will have all of the locations of their bridges, of other critical infrastructure. They'd pull in the ShakeMap, and then what it generates for them is a prioritized list of where they've got to do inspections, where they need to focus their attention.

The next product that comes out following an earthquake is PAGERs. So in this case, we're taking the shaking intensity, we're overlaying it on population to get a snapshot, a very quick look at how many people were exposed to strong shaking, very strong shaking, violent or even extreme shaking.

 22:00

This is an example from just a couple of months ago. This was an earthquake in China. You can see several thousand people exposed to violent shaking, some of the larger populations to very strong and severe, resulted in a couple of thousand fatalities.

The next generation of PAGER, which is currently a beta test version which we'll be releasing publicly in the coming months, then takes that one step further to try to make, again, this information as useful as possible and now looks at not just the number of people exposed to shaking but actual estimates, order of magnitude estimates of population of casualties and of economic losses to be able to give the emergency response organizations, aid organizations, groups like the Red Cross, Mercy Corps, others, a quick look, often communication's going to be out, there won't be reports trickling in over days, but to be able to say within 30 or 40 minutes, 'OK, this is the humanitarian disaster you need to go.'

 23:08

And the timeline in which this happens for domestic earthquakes, the first information's coming out in a minute, ShakeMaps in five to 10 minutes, PAGER results in 10 to 20, and then all of that can be fed into FEMA's loss estimations software within an hour.

Our long-term goal in building these systems is to push this information out faster and faster, the point of which, some of the information's actually getting out to distant areas before the shaking arrives, and that's called Earthquake Early Warning. It's not prediction. The earthquake's already occurred somewhere, but you can actually get the electrons out ahead of the strong shaking.

They have these systems in Japan. They're very well-developed. Actually, Mexico has this system. Bucharest has this system. But we do not yet have the system. It's one of the things we're building towards in developing our advanced national seismic system here in the US.

 24:05

After the Sumatra earthquake in 2004, we were able to straighten our networks, build out the NEIC as a 24/7 operation and, working with NOAA, build a tsunami warning center in the Caribbean.

Now, I mentioned about the west coast in the US being a plate boundary. Indeed, the whole rim of the Pacific is known as the Ring of Fire, lots of big subduction zones where the oceanic crust is diving down. You have a lot of the vast majority of the world's earthquakes and volcanoes.

Well, the Caribbean is its own little Ring of Fire. It's also ringed by plate boundaries, many of them subduction zones. The whole eastern part of the Caribbean, all of these yellow triangles here are volcanoes. A very active region.

Our part of this was to put in seismic stations throughout the region, eight different countries as well as Guantanamo Bay. It took longer to get a station installed in Guantanamo Bay than it took for the other eight countries.

 25:08

And this is the system that was in place on January 12th to be able to rapidly report on the earthquake that occurred in Haiti. This is from the White House homepage for the first several days after this earthquake showing the ShakeMap.

So here's the PAGER result for Haiti. Within about 20 minutes, the first version of this was out. It was sent to aid organizations, it was sent to the US Agency for International Development and to other countries in the region with an estimate of over two million people exposed to severe shaking. So you instantly know that this was going to be a humanitarian disaster of the first order.

You've all seen these images from Port-au-Prince. Over nearly a quarter million fatalities. This is the worst disaster in the history of the western hemisphere, over 300,000 homes damaged or destroyed and over one and a half million people affected.

 26:06

There are no building codes in Haiti. Earthquakes are not one of the hazards with which they were familiar. It's not what is part of their experience or their parents' experience or even their grandparents' experience. Because, I'll show you, earthquakes are very much a part of the history of Haiti, but not part of the recent history. And so the buildings have been designed to withstand hurricanes; they've not been designed to withstand earthquakes.

What this graph shows is time on the bottom and what's called 'moment rate'. What it is is energy release on the vertical axis. This earthquake was over in under eight seconds. All of the energy, all of the force of that earthquake hit those buildings, and they all collapsed in eight seconds. It was all over that fast. And that partly explains this tremendous loss of life.

But one thing that's so challenging about earthquakes is, then it's not over. A hurricane comes through, it passes through, it's done. Earthquakes, you've got aftershocks. 

 27:06

And what this is showing, the yellow circle there is the epicenter. This is the nucleation point for the magnitude 7 earthquake. You can see Port-au-Prince right here just about 15 kilometers away. All of these are magnitude 4 or 5 earthquakes in the days and weeks that followed.

And that was one of the big challenges from a response standpoint is that you were still having additional quakes putting already weakened buildings at further collapse hazard for those trying to do search and rescue, and moreover, there was a real concern that this wasn't it in terms of a big quake.

And so one of the things that our scientists did in the days following the earthquake was to try to understand and quantify what is the ongoing hazard. This earthquake happened on the Enriquillo fault, which you can see here running along. And this is kind of a funky diagram.

 28:00

What it's showing is this is surface, and this band is going down in depth. So the surface is here and we're going to deeper depths. Blues mean that you've released stress. So in this 50-kilometer stretch here, this is where the fault ruptured, and you've relieved stress there. The trouble is, it's a big long fault and you've actually built up stress at either end. So you've actually increased the hazard at either end of the fault. And of course the eastern end is where Port-au-Prince is.

We put out a statement in the first couple of weeks after the event and then again a month later, simply because there was panic as a result of not knowing what was coming next, and trying to at least put some numbers to help with that, how likely is it in the next 30 days, 90 days, a year that there's going to be a magnitude 5 earthquake, a magnitude 6 earthquake, a magnitude 7 earthquake.

 29:02

And we put this out in English, we put it out in Spanish, we had a French translation as well, and then we had a Creole translation. And this is the Creole translation.

The USGS and several other agencies participated in a workshop down in Miami, the purpose of which was to now say, 'OK, we're trying to recover. There's going to be a huge amount of effort.' This was an impoverished country. It did not have the resources to be resilient to this earthquake. But now, there's going to be a huge outpouring of funds and support from outside. Everybody wants to rebuild back better. How do we actually make sure that we're rebuilding back better?

There's an incredible quote from a Portuguese ship captain after Port-au-Prince was destroyed in 1770, and he said he watched people putting the stones back together, and he was watching them build the crypts for the next generation.

 30:11

How do we try to avoid that? Well, some of the key issues that were brought up at this was, first off, you need to know where the hazard is, not just the earthquake hazard, earthquakes, landslides, flooding, so that when you are relocating people, when you are rebuilding, when you're making these investments, you are doing so in a way that you're not simply putting people back in harm's way.

The second part was engineering issues. Again, you're going to have this big outpouring of funds for building hospitals, for building schools, for building infrastructure. Don't build back in a way that it's just going to be destroyed in the next event.

And then capacity-building, that you can't have people flying in, doing their work, and flying out. You actually need to have a long-term effort, and that means you've got to be building capability in Haiti. And that doesn't just mean science and engineering. That means improving the ability of the knowledge base of masons, improving the folks who are making cement, very hands-on kinds of capacity.

 31:18

And then finally, scientists always have long-term data needs.

So the first piece of this for the USGS response was to build a new hazard map. This is what the hazard map looked like for Haiti. It was based on past earthquakes, past instrumented earthquakes. And that's what the last 50 years looked like in Haiti. Not many earthquakes. It had been very quiet. Almost too quite, you might say.

This is the map that resulted from that as part of the global map that had been generated. If you look at historical earthquakes, if you go back to the 18th century to the 19th century, you can see that this Enriquillo fault, which runs right through here, as well as its partner, the Septentrional fault running through Northern Hispaniola, has a tremendous history of earthquakes.

 32:13

As I mentioned, Port-au-Prince was destroyed in 1751. Port-au-Prince was destroyed again in 1770. So you need to have that as your basis for rebuilding, that you are not going to simply assume a hazard. You need to have that spelled out, and then that needs to be translated into the building codes.

So the map on the left is a joint effort by USGS and the USAID to build a modern seismic hazard map for Haiti and the Dominican Republic. You can see the hazard associated with the Enriquillo fault and again the hazard with the Septentrional fault, which has not ruptured in this region for 150 years and, like its partner, is due.

 33:00

And this map then takes one step further. Remember I talked about how shaking can vary based on the sediments and the soils? And so this is a first-order attempt to build that in, again, so that when you're constructing these buildings, you're going to be making all these foreign investments in Haiti, you have the money to do it right, you actually will do it right.

The second part of this is the capacity-building. And this is our scientists working with colleagues in the Haitian Bureau of Mines and Energy. We actually deployed temporary stations. We're now working to make those stations permanent and handing off that responsibility for not just tracking earthquakes but also from using the shaking from these aftershocks actually understanding the variation in the shaking, again, so you can focus reconstruction where you're not simply going to be returning folks directly into that hazard.

 34:05

Now, the fourth deadliest earthquake in history was followed a month later by the fifth largest earthquake ever recorded. This is the Chilean earthquake. And I mentioned the global seismographic network earlier. And this is another kind of funky diagram.

This is showing every single station in the GSN by its distance from the epicenter. So we're just moving further and further. This is degrees around the Earth, so there's 180 degrees around the Earth. And you can see each one of these recording the earthquake all around the world, and all around the world again. Again, the entire Earth ringing like a bell from this earthquake.

This earthquake was a giant. It released 500 times more energy than the Haitian earthquake. It ripped a section of the Earth's crust where this is another one of these subduction zones, so the oceanic plate diving down against the continental plate over about 500 kilometers distance. You expose millions of people to severe shaking.

 35:11

And this is the ShakeMap for Chile here and for Haiti here. You can see totally a different scale, and yet a totally different outcome in the opposite sense. Here with a magnitude 7 earthquake, nearly a quarter million fatalities; in Chile, under 500 fatalities.

To put this in a different perspective, this is a recent study by the Inter-American Development Bank, sort of, 'What is a major disaster?' And there was a large disaster. They set the threshold at seven people per million inhabitants of a country, and that's roughly the size of Hurricane Katrina represented for the US.

The 2004 Sumatra earthquake and its resulting tsunami killed 772 people per million inhabitants in Indonesia. The tsunami alone killed almost 2,000 per million in Sri Lanka. Haiti, over 20,000 people per million inhabitants. Chile, approximately 17.

 36:20

This is a diagram that Roger Bilham put together, a professor at the University of Colorado. So here's the size of the earthquake on the bottom. This is all deadly earthquakes in the past century. Number of deaths per earthquake.

So you can see Haiti, not a particularly large earthquake. As I said, we get 15, 16, 17 magnitude 7 earthquakes a year. Here it is up at the top there. Here's Chile, one of the biggest earthquakes we've ever recorded, and the fatalities down there.

And it's a pretty simple story. No building codes in Haiti; very good, very robust building codes in Chile.

 37:03

These are a couple of modern buildings. Everybody shows the damaged ones. This is a tower where several of the stories just were completely pancaked, but the building stood. This was a building that was actually under construction and it literally just fell over. It hadn't been well-anchored to its underground parking garage and it just fell over on its side.

But overall, there are only four buildings that collapsed despite this gigantic earthquake, the shaking that lasted over two minutes. Four buildings collapsed, 50 more of them stood up, and that's what building codes are about. Building codes are about life safety. They're not about being able to reoccupy the building the next day, being able to use it again. They're about life safety. People were able to walk out of that building.

For buildings three stories or higher, the failure rate was half a percent. And for taller buildings, it was 2.8%. And to put that in comparison, the building codes in the US for this kind of shaking are designed for about a 10% failure rate. So the building infrastructure did extremely well, and the low fatality rate as a result.

 38:21

Now, there are a lot of lessons that we can take out of the Chilean earthquake, but I really just want to focus on that contrast. Because as we look to the future, there are many, many cities, in this case cities over a million inhabitants, that are located in earthquake zones, that are going to be subject in the future to strong shaking, very strong shaking, severe violent shaking. The shaking is inevitable, but the outcomes are not. And that contrast between Haiti and Chile is a very meaningful one from that standpoint.

Cities like Istanbul, Tehran, Jakarta are at tremendous risk. It will be a huge challenge to reduce that risk. But we need to recognize that a part of development, a part of sustainability is reducing the risk from disasters, and that these are ultimately acts of man, not acts of God, when it comes to whether or not there's survivability.

 39:31

So this is the challenge that we have before us as we do pursue development, as we do look into the future, is to have more Chiles and fewer Haitis.

Now, part of why we have been studying Chile very intensively, particularly the engineering community, is because we have similar subduction zones off our own coast, both off of Alaska and off of the Pacific Northwest. In fact, we had an earthquake even larger than the one that struck Chile. It just hadn't happened particularly recently.

 40:02

The map on the left is showing the subduction zone off the Pacific Northwest. It runs from Northern California, Cape Mendocino, up to British Columbia. And the black, I don't know, stretched-out jellybean shape there on top of it is the zone that ruptured in the 2004 Sumatra earthquake. We have a Sumatra-scale earthquake hazard right off of our Pacific Northwest.

And the reason we know about this is because of some just tremendous geologic sleuthing that was done by a USGS geologist named Brian Atwater back in the 1908s where he found these tsunami deposits all up and down the West Coast from Northern California up through Washington associated with forests that had all been dropped down in a sudden subsidance in between the growing seasons of 1699 and 1700. And so they'd all been dropped down and exposed to saltwater, all killed off.

 41:06

But that still just told you that there could've been several large earthquakes occurring over the course of multiple months, like the example I gave for the New Madrid. They refer to it as the 'months of terror' scenario.

But then he worked with colleagues in Japan where they have intricate records dating back many hundreds of years of all tsunamis, both tsunamis that are locally generated, so associated with big earthquake shaking, and those that they call 'orphans', where there was no shaking but a tsunami arrived. In this case, the tsunami arrived from across the Pacific. And so that's why we know that on the night of January 27th in 1700, we had a magnitude 9 earthquake off of the Pacific Northwest.

And when that earthquake repeats, we're going to have the same kind of shaking that we experienced in Chile. Minutes of shaking. And you think even just a few seconds of shaking would feel like minutes of shaking. But it's very concentrated in not sort of high-frequency sharp motions but sort of big rolling motions.

 42:09

And the buildings in Chile experienced that, and the buildings in Chile did pretty well. But there were problems. For example, infrastructure. Things like bridges. They have an interstate 5; they even call it Interstate 5 that's exactly like our Interstate 5. So we're trying to learn everything we can from the experience in Chile so that we can make our own Pacific Northwest more resilient when we face the same hazard that they did.

Now the last earthquake that I'm going to talk about is an earthquake that, in contrast to either the massive destruction that occurred in Haiti or the huge cost associated with the Chilean earthquake, this was an earthquake that could not have been put in a better place. This was a magnitude 7.2 earthquake. This is a good-size earthquake.

This is Google Earth. One of the choices is 'earthquakes' and you click there and it will give you a feed from the USGS every five minutes.

 43:11

So here's the epicenter, here's where it started. And remember, I said the size of an earthquake relates to the length that ruptures. In this case, the rupture went all the way up to here. It actually did it in two pieces, and you can see that in all of these aftershocks. There's a big concentration here and a big concentration here that actually reaches over the US border.

It's in an area that's very sparsely populated. It avoided some of the more heavily-populated agricultural areas. It gave Mexicali a shake, but not the kind of shake that a number of other faults in this area could do.

There are a couple of things that we can take away from this event. And the first one is, although it didn't have a big impact, I think there was maybe one or two fatalities from this event. It didn't have a big impact on housing, it didn't have a big impact on people, but what it did have a big impact on was agricultural infrastructure, on dikes and levies. Of course, that's the absolute lifeblood out there in the Southwest.

 44:14

And that's of concern because we face a really significant problem in Northern California in the area known as the Bay Delta. So this is east of San Francisco Bay where there's tremendous numbers of agricultural levies. These aren't big Mississippi River-strong reinforced levies. These are agricultural levies that had been built up over time. And they are very subject to failure from a process we call liquefaction where the ground basically in the shaking loses all of its strength.

So we're trying to learn everything we can from this earthquake so we can understand what the impacts are going to be of a Bay Area earthquake on those agricultural levies in the Bay Delta. And that's an issue not just for Northern California, but 40% of the drinking water supply in Southern California comes from the Bay Delta. So this is a huge issue for water supply not just in the north but also in Southern California.

 45:13

So the first thing we're trying to take away and learn what we can is the shaking impacts on levies and dikes and canals from this earthquake.

And the second one is that, as I said, you really couldn't have put it in a better place. But it also kicked some of the most dangerous faults that we have in California. Remember when I talked about Haiti, I talked about how you relieve stress in one place but you're building it up at the ends? Well, we just had a big rupture that pushed energy up into the southernmost part of California. And so that's always a point of concern.

I mentioned the Bay Delta. It's right up in this area. I talked about our seismic hazard map that looks at over 50 years what's the likelihood of shaking. Well, this is a variant on this.

 46:13

This is a 30-year projection that we did with colleagues at the Southern California Earthquake Center and the California Geological Survey, with support from the California Earthquake Authority. And it's saying in 30 years, 'What's the likelihood we're going to have a magnitude 6.7 or greater earthquake in California?' A big damaging earthquake. Well, it's pretty much 99%. So in the next three years, there's an inevitability we're going to have a large damaging earthquake.

But then the next step is, well, which are the faults that are the most dangerous and the most likely to cause a catastrophic quake? Well, one of those is the Hayward fault that runs right up the East Bay. It actually runs right through the middle of Cal Berkeley stadium. And the other is the Southern San Andreas, and that extends down all the way to Bombay Beach here on the Salton Sea. And the earthquake that we just had, its ruptured extent ends to about here. We also have the San Jacinto fault and the Elsinore fault all together here in Southern California.

 47:03

And so what I would say that we take from this Baja event is underscoring the importance and necessity of preparedness for the next big event in Southern California. And indeed that's been a major focus for the USGS over the last several years is, how do you take a hazard and make it real to people, make it real enough to people that they're going to take action?

And so we had what we call the Multi-Hazard Demonstration Project that's been led by Lucy Jones for the past four years, and the whole purpose of it is do a better job of delivering information to the people of Southern California, work with communities to deliver the information.

And the Number 1 priority from those communities was, give us scenarios so we can try to make this real. So not just look at the hazard, look at the earthquake itself, but look at the whole range of impacts that are in the earthquake, look at what the impact's going to be to infrastructure, look at what the impact's going to be to schools, how it's going to impact, for example, fire following earthquake, not just look at the one hazard but look at the whole suite of it, and play it out for Southern California.

 48:17

And so that's what they did. It's called the Great Southern California Shakeout Scenario. It's a magnitude 7.8 earthquake that starts down here on the Salton Sea and ruptures all the way up past, here's the main urban area. There's over 20 million people located in this region. And the image here is a snapshot of the simulation showing the intensity of shaking, of course the red hot colors being the ones that are the most dangerous.

This was then used for what was called the Great Southern California Shakeout. Part of it was sort of typical emergency management exercise to get folks get thinking about how they're going to deal with an event of this magnitude.

 49:04

But the other part of it was to actually get the public involved. They had the largest public preparedness exercise in US history. It was over five and a half million people participating in 2008, and then in 2009 they've brought it statewide, so now it's the Great California Shakeout, and they had nearly 7 million people participating in this.

And the whole idea here was to get people talking about the hazard, get people talking about earthquakes, because it's only if you start talking amongst your peers that you're going to do something. So a big emphasis was on schools. Majority of the participants were school-age kids. But it also involved businesses. It also involved local governments.

So the idea was that the parents would come home and they'd say, "What did you do in school today?" and the kid would say, "What did you do at work today?" and everybody would've been involved in things like, I've got here the poster for the 'Drop, Cover, and Hold On' exercise that people participated in.

 50:06

I'm going to close by showing you a short video that was generated for the Shakeout that emphasizes the basic message, which is, like what I talked about with Haiti and Chile, it's not a 'throw up your hands', 'earthquakes are inevitable, so destruction is, too'. It's, 'What you do to prepare before an earthquake is going to determine your quality of life afterwards.'

One of the key areas where we've seen real progress come from this that we were able to make this hazard real enough to people that they took action was in the area of infrastructure. Of course, our modern society is now so linked in and connected in a way that we've actually managed to generate some new vulnerabilities that we may not have had in the past.

This is showing the Southern San Andreas fault, that's the red line here, as it passes over the various, these are all of the highways coming into Los Angeles. These are your basic lifelines.

 51:13

And in particular, focus on Cajon Pass. You have highways, you have railways, you have fiber optics. You have natural gas. You have all of the gasoline that's used in Las Vegas, 80,000 gallons a day running. It's refined in Los Angeles and it's piped to Las Vegas, all of it running through this one pass.

So that means as a lifeline operator, you can't be thinking in isolation and you can't just be thinking about shaking or about rupture. You need to be worrying about wildfire, you need to be worrying about a whole range of different hazards. And you need to be talking.

The old joke out in the West is that whiskey is for drinking and water is for fighting. Well, the water utilities recognized that the ruptures were basically going to overwhelm their individual capabilities. And in general, the only time water utilities ever get together in the same room is if they're suing one another.

[Laughter]

 52:14

David Applegate: So this was really a radical thing that they checked the lawsuits at the door to come together and figure out how to build a mutual aid pack so that they're going to be able simply to have enough pipe to deal with avoiding really a long-term situation disrupting their service capabilities.

So as I said, I'm going to end with this video. It's a little bit loud. It's not your sort of basic, typical USGS product. But it's very effective. It was actually done as a volunteer effort by students at the Art Institute in Pasadena, Art Center School of Design. And I think it does a very good job of conveying the preparedness message.

 53:19

So like I said, not your typical USGS product.

[Laughter]

David Applegate: But I thought it would be a good way to end, because it really does better than I'm going to do at emphasizing both the potential impacts that an earthquake can have in Southern California, as Baja has reminded us. And indeed an earthquake can occur anywhere in the US, as reflected on our seismic hazard map.

But again, 'Life on this Dangerous Planet' is not intended to be a fatalistic statement but quite the opposite, that we really can change and we can affect their outcome. So thank you very much.

[Applause]